After the British people demonstrated their will to leave the EU in a referendum in June 2016, many questions arose on the future of the EU. In particular, the security and defence of the Union, in which the United Kingdom has always played a crucial role, will become a highly important issue for the 27 remaining Member States.

Since its origins in 1951, the European Union (EU) has always been known as an economic actor. Around the world, the EU model refers mostly to the Single Market. However, the Union now plays a role in many other domains. Over the years, it has increased its diplomatic power and its role in international affairs. This was especially illustrated with the creation of the Common Foreign and Security Policy (CFSP) under the Maastricht Treaty in 1993. As the EU was trying to assume a bigger role in international relations, France and the United Kingdom (UK), the two most crucial military actors in Europe, pushed for more cooperation in defence matters. The UK plays a decisive role in European defence, as it is the biggest financial contributor to defence within the EU. Indeed, the UK spent around 42 518 million Euros on defence, representing therefore 26% of total defence expenditure in the EU (European Defence Agency, 2016a: 4). It is, as France, a permanent Member of the United Nations Security Council, and has therefore within this institution a veto right. The UK also possesses nuclear weapons. For all these reasons, Britain is not only a major diplomatic, but also a major defence actor in Europe with worldwide recognition.

On 23 June 2016, in a referendum that was promised by then Prime Minister David Cameron, the British people decided to vote with 52% in favour of leaving the EU (The Electoral Commission, 2016). While such a vote triggers the urgent need of discussion on many issues, notably on direct democracy and on the so-called “losers” of globalisation, possible consequences of Britain leaving the EU (commonly called Brexit) are indeed worrying. Especially in the defence sector, the withdrawal of the UK’s membership from the EU could be disastrous in light of the country’s significant role in this domain. Defence matters are now more than ever necessary to be discussed, as the North Atlantic Treaty Organisation (NATO), the traditional actor ensuring European security, is stepping back, and as conflicts in the neighbourhood of Europe are intensifying and becoming increasingly numerous (Inkster, 2016: 25).

One could define the consequences of Brexit as rather worrying for the future of the EU’s defence. Indeed, many scholars assume that “Britain’s place as a key partner in the NATO and one of the EU’s two capable military powers, means a Brexit would weaken the EU’s efforts in security and defence” (Oliver, 2016: 1326). However, one could also argue Brexit represents an opportunity for European defence cooperation. When analysing Brexit’s consequences on defence cooperation it is necessary to take into account the broader picture of international relations as they are today. While the Brexit vote in the referendum happened, another major event for European security took place, that being the election of Donald Trump as the new President of the United States of America (US). President Donald Trump reiterated many times his strong will to push forward a new line for American diplomacy. He is proposing closer ties with Russia, which is sometimes regarded as the West’s hereditary enemy, and a lesser role for NATO in Europe and in the world more generally (Sanger and Yardley, 2016). This election combined with the Brexit vote translates in a new equation for European defence.

NATO as a justification against EU-level defence integration

While the UK plays a crucial role in EU defence, it has always been reluctant to further integration in this sector. Indeed, the UK has always advocated strongly against the principle of a European army. In its projection, a European army would call into question NATO’s legitimacy to ensure Europe’s security. Indeed, the Leave campaign “[warned], on the one hand, that the EU is determined to become a super-state, taking responsibility for security away from the UK and disrupting current defence and intelligence arrangements, especially those with the United States. It predicts on the other that the EU is about to be engulfed by crises with which it cannot cope” (Freedman, 2016: 7). Therefore, the UK needed to leave the boat before the creation of a supranational European army. However, such a project will remain highly utopic even without the UK’s reluctance, as other “big countries” within the EU oppose the idea of such an army (Winn, 2003: 65). Even without the UK, a real European Army will probably not see the light, at least not in our lifetime.

However, more realistic projects such as the creation of a European Operational Headquarter seem now much more plausible with Brexit than it was before. The UK has always been strongly opposed to the creation of an Operational Headquarter at the European level. Indeed they considered such headquarter as the first step towards this European army and reckoned such facilities to be redundant, as NATO already has headquarters in Belgium. Therefore, a European Operational Headquarter would suggest the end of the Berlin plus agreement of 2003 between NATO and the EU that stipulates that the EU may use NATO’s facilities to engage in its own missions and operations. As a consequence, this European Operational Headquarter would strengthen greatly the EU’s strategic independence as well as its rapid reaction capacity. Such a controversial project for Member States had for once the backup of the biggest countries in the EU, and mainly was pushed forward by France, Germany as well as Poland. By vetoing the project in July 2011 (Waterfield, 2011), the UK killed any hope to let it happen, as long as it was part of the Union.

The UK has always been very reluctant as well to improve the European Defence Agency’s (EDA) budget (Biscop, 2016: 441). The EDA budget is mostly used to finance common defence research projects within EU Member States. Why the British always opposed a budget increase for EDA can be once again explained by their refusal to let the EU put NATO in the shade. Once out, the UK will no longer be able to block an EDA budget increase. Of course, it will also no longer contribute to it neither, which could be problematic if other Member States don’t show enough willingness to replace the British position as the EU’s top defence power. The UK is the third of the participating Member States providing the most to the EDA budget, after Germany (6.4 million Euros) and France (4.7 million Euros) with its 4.6 million Euros contributions in the year 2015, which represents less than 16% of EDA’s total budget (EDA, 2016b: 29). Giving the EDA adequate financial means would be the first step towards a much more integrated defence cooperation. Indeed, if the EDA was able to launch concrete pilot projects and therefore to propose realistic investments by illustrating the necessity of spending commonly on such projects, integration in defence would come at a much more rapid pace. As of now, EDA’s failure can be partly explained by its lack of funds and therefore it does not have the necessary means to propose the projects the EU defence actually needs (see Biscop, 2016: 441-442).

Will other Member States replace the UK in its reluctance?

Many countries have been profiting from UK reluctance, as they shared the same position on European defence but did not have to show it to other EU partners and could simply wait for the UK to veto every single project. In particular, Central and Eastern European countries have for long considered NATO as being the most adequate and most legitimate actor to ensure their security against the Russian threat. Indeed, they identify behind NATO the US forces and the “umbrella of protection” it provides for such countries. The reason for advocating against the EU becoming always more involved in security and defence matters was that this could irritate NATO and the US, which could then as a response decide to step back from the European security scene.

As most Central and European countries did not believe the EU could replace NATO entirely they preferred to let the UK slow down if not completely stop the few European countries willing to integrate more in that direction. It is very questionable how such countries will position themselves on defence integration without being able to hide behind the UK’s strong stance. One could have imagined that one of them, probably Poland, could have taken over UK’s role and would have engaged more strongly against any action that could be understood as a threat to NATO’s influence. However, with Donald Trump’s elections, and his position on defence matters and an always more threatening Russia, such countries may very well decide to take the plunge and fully commit to bring forward a common European defence. The threat of a Russian invasion without any intervention from the US against it will definitely be an incentive strong enough for Central European countries to turn towards a real European security and defence force. Indeed, “Poland [already] broke with its former image of a NATO-centric, ‘Atlanticist’ nation, stirring controversy within the EU and drawing public attention to the problem of the Union’s seemingly declining global influence” (Terlikowski, 2013: 27).

Towards a Franco-German tandem

With the UK out, the Union will have to reshape itself to bring forward defence cooperation. The Franco-British partnership has always been the motor for European defence, as those two countries are the two most powerful in European military matters. In order to transform the Brexit disaster into an opportunity, at least in the defence sector, it will be necessary to revive the Franco-German tandem. The Franco-German tandem has been successful in many areas of European integration and the EU as it is today would never have been achieved without those two countries coming together. However, the French and the British have always led defence and security discussions, as they have a much closer military culture and a common conception of interventionism. Germany, because of its history, is still today very reluctant to intervene military and to operate a larger army, as it has no incentive in becoming an active security actor. Therefore, France and the UK developed strong ties in bilateral partnership. Their defence and security cooperation started with the Saint-Malo Declaration in 1998 and was renewed by the Lancaster House Treaties of 2011.

With Brexit, France will have to find a new partner within the EU and therefore to re-orientate itself towards Germany. What would necessary emerge from a European defence based on a Franco-German motor, would be a much more balanced European security actor. Indeed, Germany will impose a strong civilian aspect, that the EU already has now, and France will push forward to strengthen military assets. Common positions between France and Germany should not be undermined. In the case of the US-led intervention in Iraq in 2003, Berlin and Paris refused to participate, while London strongly supported the US. As Richard G. Whitman (2016: 7) underlined with regard to the Iraq crisis, “[w]ith the UK in opposition to Germany, France and a substantial minority of the EU’s other member states, Blair was widely condemned by continental European governments for dividing the EU on a key foreign policy issue”. The newly elected French President Emmanuel Macron in May 2017 has shown a strong will to push towards more defence integration within the EU and notably supported the creation of a European defence fund designed to co-finance defence research projects. He seeks to see Germany and France leading the path towards a more integrated EU defence.

UK may leave the EU, but it will remain in Europe – and in NATO

While Brexit might provide a huge opportunity for EU’s security and defence cooperation, cooperation with the UK will be far from over in such a sector. France and the UK still have their bilateral cooperation, which will continue after the Brexit as former French President François Hollande pointed out (Carraud, 2016), even if France’s incentive to bring them forward will reasonably diminish. Naturally, the UK will remain in NATO and therefore cooperation will continue. Indeed, the dialogue between NATO and CFSP has been increasing for many years and is still developing. While the two were for long conceived as competing with one another, this is far from being the case now. Indeed, there is no reason to see EU-NATO relationship as a competition one. This should be described rather as a complementing relationship. The EU does remain a major civilian actor, while NATO is solely focused on military forces. Therefore, new links with the UK within NATO will not have to be contentious. In fact, if NATO does step back from the European security scene, it will also be in the UK’s interests that the EU effectively ensures security in the continent. Furthermore, the UK will still be able to participate to CSDP mission that might hold its interests abroad.

One could speculate that, while the UK will step back from the European scene and the US will be less active within NATO, this could leave the door open for the British to increase their role within NATO and support if not take over US actions abroad. As François Heisbourg (2016: 19) stated, Brexit will “certainly not remove Britain from Europe’s troubles [which will] impose themselves uninvited onto a post-Brexit Britain’s agenda, because Britain is where it is: off the coast of Europe. For a medium-sized, post-imperial power, there is no escaping the fact that geography is destiny”.

After Brexit, the EU will have to refocus and concentrate solely on its neighbourhood, in order to stay efficient and effective. Indeed, without UK’s contribution to the defence budget, the EU will be obliged to prioritise its action and focus on what it truly needs to ensure its own security. Terlikowski assumed that “[w]ithout the UK onboard, it will no longer be possible for the Union to function as a respected global security actor, especially in security matters” (2013: 29). However, one could argue that such a withdrawal of certain world zones would not question its role as a credible global security actor, as long as, where the EU intervenes, it stays efficient and delivers concrete positive results. It is in the EU’s interests to ensure stability in its neighbourhood as we saw with the refugee crisis, which is a direct consequence of crises in neighbouring countries.

Outlook and Conclusion

It is fair to assume that in general Brexit will have negative consequences on the EU and the UK altogether. However, as this willingness to leave the EU was decided democratically by the British people (even if the campaign methods for the referendum can and should be highly criticised), it would be absolutely wrong to deny their say and refuse their withdrawal from the EU. On the contrary, as one cannot change the facts, one can still decide on their outcome. Among other reforms, by transforming Brexit into an opportunity for European defence, the Union could save itself from crumbling apart. Above all, such cooperation is today urgently needed and became a matter of international security with regard to an always more threatening Russia and the US under Donald Trump unwilling to intervene in favour of European security.

In order to achieve such effective cooperation, EU Member States will have to reshape their participation within EU defence. Central and Eastern European countries will have to accept the urgent need of an effective EU defence to protect the EU’s Eastern borders near Russia. Germany will need to rethink its tradition towards military power, as its participation will become crucial. As of France, the difficulty will be high, as it will need to increase its participation in EU defence to balance the UK’s withdrawal, while at the same time accept other EU countries getting more involved in defence matters who might question France’s approach to such domains.

Brexit does represent the biggest crisis the Union has ever faced and many have predicted shortly after the referendum the end of the Union. Whether to make of this crisis the EU’s grave or EU’s next opportunity is up to Member States and the European peoples.

Aller plus loin

Primary sources

European Defence Agency (2016b) 2015 Financial Report, published on 30 June 2016.

European Defence Agency (2016a) National Defence Data 2013-2014 and 2015 (est.) of the 27 EDA Member States, published in June 2016.

Winn, Neil (2003) Towards a Common European Security and Defence Policy? The Debate on NATO, the European Army and Transatlantic Security, Geopolitics. Summer 2003, Volume 8 Issue 2, 47–68, doi: https://doi.org/10.1080/714001032